Front module for a motor vehicle

ABSTRACT

The invention relates to a front module for a motor vehicle, wherein the front module is in one piece and is composed exclusively of plastic.

RELATED APPLICATIONS

This application claims priority for German Patent Application #DE102010 029 789.5 filed on Jun. 8, 2010 and the same is incorporated hereinas if fully set forth.

FIELD OF THE INVENTION

The invention relates to a front module for a motor vehicle and to amethod for producing a front module.

BACKGROUND OF THE INVENTION

Generally known from the prior art are front modules for motor vehicles,which front modules are composed entirely of metal. Such front moduleshave generally been credited with the advantage of having highmechanical stability. A disadvantage of such front modules is howeverthe high weight on account of the use of metal. Furthermore, such frontmodules must for example additionally be provided, in a complex manner,with corrosion protection, which increases the production costs ofcorresponding front modules.

Also known from the prior art, for example from EP 1 612 024 A1, arecomposite components having a carrier component and a covering componentcomposed of plastic and having arranged between said components areinforcement component composed of metal.

SUMMARY OF THE INVENTION

In contrast, the invention is based on the object of providing a frontmodule for a motor vehicle and also a method for producing a frontmodule.

The objects on which the invention is based are achieved in each case bymeans of the features of the independent patent claims. Preferredembodiments of the invention are specified in the dependent claims.

A front module for a motor vehicle is specified, wherein the frontmodule is in one piece and is composed exclusively of plastic. Here, usemust be made of a high-strength plastic, wherein high mechanicalstability of the front module is ensured on account of its being in onepiece. Because only plastic is used, it is for example possible toprovide any desired shapes and radii of the front module. Complexlacquering for the purpose of providing corrosion protection is likewisedispensed with. Furthermore, a corresponding front module has asignificantly lower inherent weight than a front module whichadditionally has metal. In this way, it is ultimately possible for theoverall weight of a vehicle to be reduced, which firstly lowers theenergy consumption of the vehicle and secondly results in higheracceleration values of said vehicle for the same drive power.

According to one embodiment of the invention, the front module has atrapezoidal shape with two horizontal support elements which are spacedapart from one another and two vertical support elements which arespaced apart from one another, wherein at least two of the supportelements are connected to one another by transverse struts. It ispointed out that, in the invention, the expression “trapezoidal” shouldnot be understood to mean a mathematically exact trapezoidal shape. Saidexpression should rather be understood to mean that the front module iscomposed substantially of four sides, wherein said sides, similarly tothose of a trapezium, are correspondingly aligned parallel to orinclined with respect to one another. This therefore however alsoincludes embodiments which have, for example with regard to one of saidsides, a significantly elongated V-shape or the like.

It is also pointed out that the expressions “horizontal” and “vertical”serve merely for general definition and do not restrict the alignment ofthe support elements, for example in relation to a vehicle body orgenerally in relation to a front module.

The use of transverse struts has the advantage that forces acting on theindividual support elements can be distributed in an efficient mannerover the entire front module. The mechanical stability of the frontmodule is significantly increased in this way.

According to one embodiment of the invention, the upper horizontalsupport element is connected by the transverse struts to the verticalsupport element or to the lower horizontal support element. This has theadvantage that normally high forces acting on the upper horizontalsupport element can be dissipated effectively over the entire frontmodule. In this way, the stability of the upper horizontal carrierelement need not imperatively be so high that forces acting on saidsupport element can correspondingly be dissipated to the verticalsupport elements. Although the total mass of the front module isincreased as a result of the introduction of the transverse struts, thetotal weight can however be reduced overall in turn as a result of theweight saving on account of the fact that the horizontal upper supportelement can be formed with lower stability.

According to a further embodiment of the invention, the support elementsare composed of a first plastic and the transverse struts are composedof a second plastic. Here, the first plastic is significantly lessstrong than the second plastic. This has numerous advantages.

Firstly, this yields a significant cost saving, because high-strengthand expensive plastics are used only where correspondingly high forcesneed to be conducted. As already mentioned above, forces acting inparticular on the upper horizontal support element are dissipated viathe transverse struts to the front module, such that it is adequate toensure particularly high stability and stiffness of the transversestruts. A further advantage is attained if the first plastic is aplastic which can be deformed in the event of a collision of a personagainst the front module. In other words, the use of two plastics ofdifferent hardness can therefore serve to provide pedestrian protection.

For example, it may be specified in this regard that, above a collisionspeed of 30 kilometres per hour of a person against the front module, adeformation of the latter occurs such that, in this way, the collisionenergy is reduced and furthermore the risk of injury for certain typesof injury decreases. In particular, it may be provided for this purposethat the upper horizontal support element is designed especially toprovide such pedestrian protection. That is to say, if a pedestriancollides with the engine hood arranged thereabove, the collision energycan be dissipated by the correspondingly regulated deformation of theupper horizontal support element.

According to a further embodiment of the invention, at least one of thesupport elements has at least a first and a second section, wherein thefirst section is composed of the first plastic and the second section iscomposed of the second plastic. In this way, local sections of the frontmodule can be mechanically reinforced. In this way, it is possible forexample to make allowance for the fact that forces can act on differentsections of the front module in a particularly significant way.

The front module has for example longitudinal support plates, preferablylikewise produced from plastic and integrally connected to the frontmodule. Said longitudinal support plates are arranged on the verticalsupport elements and are provided for fastening the front module to avehicle body. If in particular the longitudinal support plates are nowarranged on the vertical support elements at the level of the connectionpoints between the respective vertical support elements and thetransverse struts, a transmission of force from the front module to thevehicle body takes place to a high degree via said longitudinal supportplates. If, therefore, the longitudinal support plates and also theregions of the connection points of the respective vertical supportelements and the longitudinal support plates are now composed of thesecond plastic, it is ensured that no deformation of the front moduleoccurs at the stated points on account of the high forces acting. Inother words, high strength of the front module is ensured in this way.

It may thus be summarized that, in such an embodiment, the entire frontmodule is monolithic, that is to say in one piece, and is composedexclusively of plastic. Here, said front module notionally comprisesboth the horizontal and vertical support elements and also thetransverse struts and the longitudinal support plates. Such a frontmodule may be produced for example in a two-component injection-mouldingprocess in substantially two working steps, as a result of which a frontmodule can be produced in a cost-effective way. Welding and othermethods for connecting individual elements of the front module to oneanother are therefore dispensed with.

In this connection, it is also pointed out that the present invention isnot restricted to the use of only two plastics. It is also possible formore than two types of plastics to be used. For example, the horizontalsupport elements may be produced from a different plastic material thanthe vertical support elements. The longitudinal support plates may alsohave a different plastic material, which makes particular allowance forthe high forces acting on the longitudinal support plates.

According to a further embodiment of the invention, the second plasticis encapsulated by injection moulding by the first plastic. Here,“encapsulated by injection moulding” should not be understoodrestrictively to mean that the second plastic is completely enveloped bythe first plastic. It is also possible in principle in this regard forthe second plastic to be partially surrounded by the first plastic. Thishas the advantage that, similarly to the steel reinforcement in aconcrete wall, use can be made both of the mechanical properties of thefirst plastic and also those of the second plastic. For example, if onaccount of the high mechanical stability the second plastic is morebrittle and can be subjected only insufficiently to bending loads, it ispossible by means of the combination with the first plastic and thelower mechanical stiffness thereof to profit from the fact that, as aresult of the combination, an element is produced which has excellentmechanical properties both under compressive loading and also underbending loading. The overall stability of a correspondingly producedfront module is thereby significantly increased.

According to a further embodiment of the invention, the front modulealso has a receptacle for a lock for a bonnet of a motor vehicle,wherein the receptacle is constructed on the upper horizontal supportelement. The second section between the connection points of thetransverse struts to the upper horizontal support element may forexample serve for this purpose. In general, at least one of the supportelements has at least a first and a second section, wherein the firstsection is composed of the first plastic and the second section iscomposed of the second plastic.

The connection of a receptacle for a lock for a bonnet of a motorvehicle to the upper horizontal support element has the advantage thatforces acting on the front module in particular as a result of theclosure of an engine hood can be absorbed and distributed over the frontmodule as a whole in an effective manner. Here, if parts of the frontmodule additionally serve for pedestrian protection, the correspondingregion of the upper horizontal support element may be designed suchthat, as described above, corresponding impact energy can be dissipatedfrom the bonnet to the front module, and energy dissipationsimultaneously takes place.

In a further aspect, the invention relates to a method for producing afront module as described above by means of a two-componentinjection-moulding process, wherein the method has the following steps:

-   -   a) providing an injection-moulding device having a rotatable        drum, wherein the drum has at least two identical mould cores        offset with respect to one another,    -   b) closing one of the mould cores by means of a first nozzle        element, wherein the first nozzle element is designed for the        injection of plastic, wherein a first cavity is formed by the        mould core closed by means of the first nozzle element and the        nozzle element, wherein the mould core which is not closed off        remains empty,    -   c) injecting the second plastic into the first cavity in order        to obtain an injection-moulded part,    -   d) opening the mould core containing the injection-moulded part        by removing the first nozzle element, wherein the        injection-moulded part remains in the mould core,    -   e) rotating the drum,    -   f) closing the empty mould core by means of the first nozzle        element and closing the mould core containing the        injection-moulded part by means of a second nozzle element,        wherein the second nozzle element is designed for the injection        of plastic, and the mould core containing the injection-moulded        part, the injection-moulded part and the second nozzle element        form a second cavity,    -   g) injecting the second plastic into the first cavity in order        to obtain a further injection-moulded part, and injecting the        first plastic into the second cavity in order to obtain the        front module,    -   h) opening the mould core containing the front module by        removing the second nozzle element, withdrawing the front module        from the cavity such that an empty mould core is formed, and        repeating steps d-h.

Embodiments of the invention have the advantage that corresponding frontmodules can be produced in a continuous manner: that is to say, whilesteps d-h are repeated, production both of the injection-moulded partand also of the front module takes place continuously, wherein theinjection-moulded part is integrated in the front module. It is possiblein particular to realize a mass production process in this way.

Furthermore, such a method has the advantage that the production of thefront module is made possible in a space-saving manner through the useof the rotatable drum. Complex production lines for conveyinginjection-moulded parts between different cavities are eliminated.

According to a further embodiment of the invention, theinjection-moulded part is encapsulated by injection moulding by thefirst plastic.

According to a further embodiment of the invention, the first and thesecond nozzle element are movable only in the radial direction of thedrum. In other words, the first and second nozzle elements perform onlya movement for opening and closing the connection of the first andsecond cavities. Movements which for example follow the rotation of thedrum thereby become unnecessary, whereby in other words the first andsecond nozzle elements can be designed to be substantially positionallyfixed. A cumbersome movement of the nozzle element in a correspondinginjection-moulding device is then not necessary. This simplifies thestructural design of a corresponding injection-moulding device.

These and other aspects of the disclosed subject matter, as well asadditional novel features, will be apparent from the descriptionprovided herein. The intent of this summary is not to be a comprehensivedescription of the claimed subject matter, but rather to provide a shortoverview of some of the subject matter's functionality. Other systems,methods, features and advantages here provided will become apparent toone with skill in the art upon examination of the following FIGUREs anddetailed description. It is intended that all such additional systems,methods, features and advantages that are included within thisdescription, be within the scope of any claims filed later.

BRIEF DESCRIPTION OF THE FIGURES

Preferred embodiments of the invention will be explained in more detailbelow with reference to the drawings, in which:

FIG. 1 shows a schematic view of a motor vehicle having a front module,

FIG. 2 shows a schematic view of a front module,

FIG. 3 shows a schematic view of a front module,

FIG. 4 shows a schematic illustration of method steps for producing afront module as described above,

FIG. 5 a shows a schematic illustration of method steps for producing afurther embodiment of a front module as described above.

FIG. 5 b shows a schematic illustration of method steps for producing afurther embodiment of a front module as described above.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Below, elements which correspond to one another in the embodiments beloware denoted by the same reference numerals.

FIG. 1 shows a schematic view of a motor vehicle 100 having a frontmodule 108. The motor vehicle 100 has a body which has inter alia amudguard support 102 and an engine support 104.

For the fastening of the front module 108, it has longitudinal supportplates 110. Said longitudinal support plates 110 may for example bescrewed, as sketched in FIG. 1, or fastened generally to the enginesupport 104.

Also shown in FIG. 1 is a receptacle 106 for a lock for a bonnet of themotor vehicle 100. This will however be discussed in detail furtherbelow with reference to FIG. 3.

FIG. 2 shows a schematic view of a front module 108. All the elements ofthe front module 108 shown in FIG. 2 are formed in one piece with oneanother and consist exclusively of plastic. The front module 108 has atrapezoidal shape with two horizontal support elements 200 and 202 whichare spaced apart from one another and two vertical support elements 204which are spaced apart from one another. The upper horizontal supportelement 200 and the vertical support elements 204 are connected to oneanother by transverse struts 206. Here, the transverse struts 206consist of a plastic material which has a higher strength than theplastic material used for the support elements 200, 202 and 204.

The front module 108 also has two longitudinal support plates 110. Saidlongitudinal support plates 110 are arranged on the vertical supportelements 204 and serve, as described above, for fastening the frontmodule to a vehicle body (cf. FIG. 1). Here, the longitudinal supportplates 110 are arranged on the vertical support elements 204 at thelevel of the connection points between the respective vertical supportelements 204 and the transverse struts 206.

FIG. 3 shows a further embodiment of a front module 108 in a schematicillustration. In the same way as the front module described with regardto FIG. 2, the front module 108 in FIG. 3 also has a trapezoidal shape,wherein all of the elements illustrated in FIG. 3 are formed in onepiece with one another and consist exclusively of plastic, that is tosay in particular do not have metal reinforcements. In contrast to FIG.2, the upper horizontal support element 200 and the vertical supportelements 204 have different sections. With regard to the support element200, in section 302 between the connection points of the transversestruts 206 to the upper horizontal support element 200, use is made of aplastic which has the same material as that used for the transversestruts 206. The vertical support elements 204 have a region 304, whereinsaid region 304 is formed between the areal connection points(connection sections) of the respective vertical support elements 204and the longitudinal support plates 110. Said regions 304 are alsoproduced from the high-strength plastic material used for the transversestruts 206.

The front module 108 therefore consists, overall, of two plasticcomponents, specifically a high-strength plastic component for theregions 304 and 302 and the transverse struts, and also a plasticcomponent of lower hardness for the other support elements 200, 202 and204.

If for example high forces now act on the region 302, no deformationtakes place in said region and said forces are dissipated in aneffective manner via the transverse struts 206 and the region 304 to thelongitudinal support plates 110.

Also indicated in FIG. 3 are cutouts 300 which serve for the leadthrough of fastening means for fixing the longitudinal support plates onthe vehicle body (cf. FIG. 1). It is however pointed out that parts ofthe front module 108 may have further cutouts, for example also with anintegrated plastic thread. If such cutouts are provided on high-strengthregions of the front module 108, these may be used for receivingfastening means for the retention of further vehicle elements.Conceivable here would be the retention of for example different fluidcontainers such as containers for washer fluids, brake fluids or thelike.

Also shown in FIG. 3 is a receptacle 306 with cutouts 308. Saidreceptacle 306 serves for receiving and fastening a lock of a bonnet.The lock can be fixed to the front module 108 via the cutouts 308. Sincethe receptacle 306 is situated in the high-strength region 302 of thefront module 108, it is ensured that forces acting on the front module108 for example during the closure of the bonnet do not lead to adeformation of the front module 108. It is pointed out here that boththe region 302 and also the receptacle 306 are illustrated on an overdimensioned scale in FIG. 3. This however serves merely for illustrativepurposes. In reality, said regions will be significantly narrower so asto ensure that, to the sides of said regions, forces acting on thesupport element 200 can lead to a targeted deformation of the supportelement. As described above, this serves for example for pedestrianprotection. It is nevertheless possible in a cheap manner to provide alightweight and highly stable front module.

FIG. 4 schematically shows different method steps for producing a frontmodule as described above using for example a two-componentinjection-moulding process. Here, the process is carried out by means ofa device 406. The device 406 has a rotatable drum 410, wherein said drumhas two identical mould cores offset with respect to one another by180°. Said mould cores are not illustrated in any more detail in FIG. 4.In step 400, both an injection-moulded part 412 consisting of ahigh-strength plastic and also a front module 108 have already beenproduced in a preceding cycle using said mould cores, wherein said frontmodule 108 partially has a further injection-moulded part of highmechanical strength and otherwise has a plastic which has a lowerstrength of the plastic of the injection-moulded part.

In step 402, the removal of the finished front module 108 firstly takesplace, wherein the two components of the front module can now be clearlyseen—specifically firstly the component 408 corresponding to theinjection-moulded part of high mechanical strength and the horizontaland vertical support elements consisting of a plastic of low strength.The front module obtained in this way may for example thereupon beequipped for use in a motor vehicle.

In a step 404 after step 402, the rotatable drum 410 is rotated through180°. As a result, the injection-moulded part 412 situated in thecorresponding mould core comes to rest in the position shown in step404. If the mould cores are now closed off by means of correspondingnozzle elements, cavities 416 and 418 are formed in this way, asschematically illustrated in FIG. 4. Here, a part of the cavity 416 isthe injection-moulded part 412. The cavity 418, in contrast, iscompletely empty, because the injection-moulded part 408 previouslysituated therein was extracted, together with the finished front module108, in step 402.

In step 414, the method returns to step 400, in which an injection takesplace into the cavities 416 and 418. In this way, firstly the emptycavity 418 is completely filled with the high-strength plastic in orderto form a new injection-moulded part 412. Furthermore, theinjection-moulded part 412 shown with regard to step 404 is encapsulatedby injection moulding by a plastic of lower strength, such that here, afront module 108 is newly formed in the cavity 416. For betterunderstandability, at the transition from step 404 to step 400 via step414, the injection-moulded part 412 to be encapsulated by injectionmoulding was re-designated as an injection-moulded part with thereference numeral 408.

In step 400, the method starts again from the beginning:

-   -   removing the two nozzle elements in order to release the newly        produced injection-moulded part 412 and the newly produced front        module 108,    -   removing the front module 108,    -   rotating the drum 410 through 180°,    -   closing the mould core 418, which has been freed up as a result        of the removal of the front module, at the nozzle element in        order to form a cavity,    -   closing the mould core, which contains the injection-moulded        part 412, by means of a nozzle element in order to form a        further cavity 416,    -   filling the cavity 418 with the high-strength plastic by        injection and filling the cavity 416 with the lower-strength        plastic by injection.

Said method is carried out cyclically.

FIG. 5 shows a comparison of a conventional production process (FIG. 5a) and the production process of FIG. 4 for producing a front module asdescribed above using for example a two-component injection-mouldingprocess. Here, in contrast to FIG. 4, reinforcement regions 304 (cf.FIG. 3) are additionally provided on the vertical support elements ofthe front module 108.

Conventionally (FIG. 5 a), it was necessary for this purpose for theinjection-moulded part 408 and the reinforcement regions 304 to beproduced separately from the high-strength plastic, inserted into acorresponding cavity by robot means, and thereupon encapsulated byinjection moulding by the plastic of lower strength. The finished frontmodule thereby obtained (not shown in FIG. 5 a) subsequently had to beremoved again from the die.

In contrast thereto, the method shown in FIGS. 4 and 5 b eliminates theneed for parts to be removed from dies and placed into other dies byrobot means. In the case of FIG. 5 b, in contrast to the methodexplained in FIG. 4, rotatable special cavities are provided whichpermit the production of vertical reinforcement regions 304, which canthereupon be encapsulated by injection moulding by the plastic of lowerstrength. In this respect, the method explained in FIG. 4 also permitsthe addition, section by section, of reinforcements using specialcavities. Said embodiment of the invention is particularly advantageousbecause, in this way, reinforcement regions can be formed at a pluralityof locations on the front module with little production outlay by virtueof said reinforcement regions initially being produced in the specialcavities and then, in the next step, being introduced by means of arotational movement into the main cavity for encapsulation by injectionmoulding.

LIST OF REFERENCE NUMERALS

100 Motor vehicle

102 Mudguard support

104 Engine support

106 Lock receptacle

108 Front module

110 Longitudinal support plate

200 Upper horizontal support element

202 Lower horizontal support element

204 Vertical support element

206 Transverse strut

300 Cutout

302 Reinforced region

304 Reinforced region

306 Lock receptacle

308 Cutout

400 Step

402 Step

404 Step

414 Step

406 Injection-moulding device

408 Injection-moulded part

410 Drum

412 Injection-moulded part

416 Cavity

418 Cavity

1. An apparatus for a motor vehicle, wherein the apparatus comprises: afront module in one piece and composed exclusively of plastic, whereinthe front module has a trapezoidal shape, the front module furthercomprising: two horizontal support elements which are spaced apart fromone another, wherein at least one of the two horizontal support elementsis an upper horizontal support element; two vertical support elementswhich are spaced apart from one another, wherein at least two of thesupport elements are connected to one another by transverse struts,wherein the support elements are comprised of a first plastic and thetransverse struts are comprised of a second plastic, wherein the firstplastic is significantly less strong than the second plastic; at leasttwo longitudinal support plates, wherein the longitudinal support platesare arranged on the vertical support elements and are provided forattaching the front module to a vehicle bodywork, wherein thelongitudinal support plates are arranged at the level of the connectionpoints between the respective vertical support elements and thetransverse struts on the vertical support elements.
 2. The apparatusaccording to claim 0, wherein the upper horizontal support element isconnected by the transverse struts to the vertical support elements orto the lower horizontal support element.
 3. The apparatus according toclaim 0, wherein at least one of the support elements has at least afirst section and a second section, wherein the first section iscomprised of the first plastic and the second section is comprised ofthe second plastic.
 4. The apparatus according to claim 3, wherein atleast the upper horizontal support element has the first section and thesecond section, wherein the second section is formed between theconnection points of the transverse struts to the upper horizontalsupport element.
 5. The apparatus according to claim 0, wherein at leastthe vertical support elements have the first a first section and asecond section the second sections, wherein the second section is formedbetween the connection points of the respective vertical supportelements and the longitudinal support plates.
 6. The apparatus accordingto claim 1, additionally having a receptacle for a lock for a bonnet ofthe motor vehicle, wherein the receptacle is constructed on the upperhorizontal support element.
 7. The apparatus according to claim 0,wherein the first plastic is a plastic which can be deformed whensomething impacts against the front module.
 8. The apparatus accordingto claim 0, wherein the second plastic is encapsulated by injectionmoulding by the first plastic.
 9. A method for producing a front modulefor a motor vehicle, wherein the front module is in one piece and iscomposed exclusively of plastic, the method comprising the followingsteps: a) providing an injection-moulding device having a rotatabledrum, wherein the drum has at least two identical mould cores offsetwith respect to one another; b) closing one of the mould cores by afirst nozzle element, wherein the first nozzle element is designed forthe injection of plastic, wherein a first cavity is formed by the mouldcore closed by the first nozzle element, wherein the mould core which isnot closed off remains empty; c) injecting a second plastic into thefirst cavity in order to obtain an injection-moulded part; d) openingthe mould core containing the injection-moulded part by removing thefirst nozzle element, wherein the injection-moulded part remains in themould core; e) rotating the drum; f) closing the empty mould core by thefirst nozzle element and closing the mould core containing theinjection-moulded part by a second nozzle element, wherein the secondnozzle element is designed for the injection of plastic, and: the mouldcore containing the injection-moulded part and the injection-mouldedpart, the empty mould core and the second nozzle element form a secondcavity; g) injecting the second plastic into the first cavity in orderto obtain a further injection-moulded part, and injecting a firstplastic into the second cavity in order to obtain the front module; h)opening the mould core containing the front module by removing thesecond nozzle element, withdrawing the front module from the cavity suchthat an empty mould core is formed, and repeating steps d) to h). 10.The method according to claim 9, wherein the injection-moulded part isencapsulated by injection moulding by the first plastic.
 11. The methodaccording to claim 9, wherein the first nozzle element and the secondnozzle element are movable only in the radial direction of the drum. 12.The apparatus according to claim 2, additionally having a receptacle fora lock for a bonnet of the motor vehicle, wherein the receptacle isconstructed on the upper horizontal support element.
 13. The apparatusaccording to claim 3, additionally having a receptacle for a lock for abonnet of the motor vehicle, wherein the receptacle is constructed onthe upper horizontal support element.
 14. The apparatus according toclaim 4, additionally having a receptacle for a lock for a bonnet of themotor vehicle, wherein the receptacle is constructed on the upperhorizontal support element.
 15. The apparatus according to claim 2,wherein the first plastic is a plastic which can be deformed when aperson impacts against the front module.
 16. The apparatus according toclaim 3, wherein the first plastic is a plastic which can be deformedwhen a person impacts against the front module.
 17. The apparatusaccording to claim 6, wherein the first plastic is a plastic which canbe deformed when a person impacts against the front module.
 18. Theapparatus according to claim 2, wherein the second plastic isencapsulated by injection moulding by the first plastic.
 19. Theapparatus according to claim 6, wherein the second plastic isencapsulated by injection moulding by the first plastic.
 20. Theapparatus according to claim 9, wherein the first nozzle element and thesecond nozzle element are movable only in the radial direction of thedrum.